WO2018055132A1

WO2018055132A1 - Flow plate for a humidifier

Info

Publication number: WO2018055132A1
Application number: PCT/EP2017/074126
Authority: WO
Inventors: Rainer Glück; André SPEIDEL
Original assignee: Reinz-Dichtungs-Gmbh
Priority date: 2016-09-23
Filing date: 2017-09-22
Publication date: 2018-03-29
Also published as: DE202016105307U1; CA3037709A1; JP6790321B2; CN109982771B; US20190305336A1; US11631869B2; DE112017004768A5; JP2019533282A; CN109982771A

Abstract

The invention relates to a flow plate (22; 47; 52) for a humidifier (1), having flow fields (28, 29) on both mutually opposite flat sides (21, 27) of the flow plate (22; 47; 52). Humidifiers of this kind are used in particular for humidifying process gas for an electrochemical system or in HVAC applications. Conventional humidifiers have lower power since an exchange of humidity usually takes place only between the layers immediately adjacent to the water exchange membranes. The flow plate proposed here has a multiplicity of through-openings (40, 48), wherein the through-openings (40, 48) are designed such that a perpendicular projection of the through-openings (40, 48) onto a plane oriented parallel to the plane of the flat surface of the flow plate (22; 47; 52) has a non-vanishing area, so that gas passing through the through-openings (40, 48) effects, at least in part, mixing of gas guided in the flow fields (28, 29) perpendicular to the plane of the flat surface of the flow plate (22; 47; 52). The through-openings (40, 48) improve the power of the humidifier, thus permitting a lower number of flow plates and therefore a more lightweight and more compact design.

Description

Flow plate for a humidifier

The present application relates to a flow plate for a humidifier, which is preferably for humidifying process gas, and to a humidifier with such a flow plate, for example in electrochemical systems. The electrochemical systems mentioned can be, for example, a fuel cell system, an electrochemical compressor, an electrolyzer or the like. In addition to applications in the field of electrochemical systems humidifiers are used for the treatment of air in the field of building services and air management in vehicles, d. H. in an area which is summarized under the English term "heating, ventilation and air conditioning" (HVAC), ie heating, ventilation and air conditioning.

Such humidifiers are used, for example, for humidifying process gas for fuel cells, which are operated with molecular hydrogen and / or oxygen or air for power generation. The for the Operation of such fuel cell usually used proton exchange membranes need to increase the durability and improve the efficiency of stable conditions as possible with respect to the temperature and humidity. For this reason, the process gases supplied to the fuel cell are usually set to a desired stable degree of humidification in a humidifier. Such a humidifier has flow plates, which are usually provided on their flat sides with flow fields for guiding a gas. The flow fields can z. B. Channel structures, wherein the channels to a water transfer medium, typically in the form of a water-permeable

Membrane or in the form of a membrane composite with a water-permeable membrane, adjacent.

Such an arrangement usually provides a plurality of stacked flow plates, between each of which water transfer membranes or

Membrane networks are arranged with water transfer membranes. In addition to a water transfer membrane, a membrane composite typically comprises at least one gas diffusion layer or GDL as support medium. For example, a GDL can be arranged on each side of the transfer membrane. The GDL may be formed, for example, as a non-woven fabric, as a fabric or scrim. An important feature of the membranes is that they are gas impermeable, but allow the exchange of moisture between the water transfer membrane and the surrounding gas. It can be provided, for example, that in each case on one side of a

Water Transfer Membrane or a membrane composite a wetter gas is passed through the flow field of an adjacent flow plate and on the opposite side of the water transfer membrane a flow field of a second flow plate is flowed through by a drier gas. In this case, the humid gas on one side of the

Water transfer membrane or membrane composite moisture to the membrane, while on the opposite side of the membrane releases moisture to the drier gas. The flow fields arranged on both sides of a water transfer membrane together with the water transfer membrane arranged between them or with the membrane composite arranged between them in each case form a humidification cell. The water transfer membrane causes a substantial part of the cost in the manufacture of the described humidifiers, so that it is usually desired to minimize the area of the water transfer membranes and thus also the area of the flow plates. The efficient one

Guiding the gas through the flow fields of the flow plates is therefore of crucial importance, because a predetermined degree of humidity of the gas should be reliably adjusted by transfer of moisture across the membrane on the smallest possible exchange surface.

From the state of the art, for example the German utility model DE 20 2014 006 480 U1, a design of the channels within flow plates of a humidifier is known in this connection, which exerts a favorable influence on the flow of the gas and thus permits extensive moisture exchange with the water transfer membrane ,

The present innovation is based on the background of the prior art, the task of creating flow plates for a humidifier, which allow in a more efficient manner, the exchange of moisture over a water transfer membrane.

This object is achieved by a flow plate for a humidifier according to claim 1 and by a humidifier according to claim 24 with a variety of such flow plates. Specific embodiments are described in the subclaims.

So proposed is a flow plate for a humidifier, in particular for a humidifier for humidifying process gas for an electrochemical system or for a humidifier for HVAC applications. At its two opposite flat sides, the flow plate has flow fields for guiding a fluid, in particular for guiding a gas along the flow plate. The flow fields can z. B. have channel structures. Preferably, in the region of the flow fields, a multiplicity of passage openings are formed in the flow plate, in such a way that a vertical projection of the passage openings is formed. gene on a plane parallel to the plane plane of the flow plate aligned plane has a non-vanishing surface. For example, the through openings may be formed in a portion of the flow plate that includes an angle of less than 90 degrees and preferably more than 0 degrees with the plane surface plane of the flow plate. However, it is also possible for such a section to run in the planar plane of the flow plate or parallel to the planar surface plane of the flow plate.

In this way, the gas passing through the passage openings from the first flow field into the second flow field on the opposite flat side can cause a mixing of the gas carried in the flow fields perpendicular to the plane of the plane of the flow plate. This in particular promotes the formation of a homogeneous moisture distribution within the guided in the flow fields along the flow plate gas perpendicular to the plane plane of the flow plate and avoids that the water exchange takes place only between the membrannahen plane. In this way, the rate of water transfer across an adjacent membrane can be maximized. Thus, the surfaces of each arranged between adjacent flow plates membranes and thus the cost of producing the humidifier can be significantly reduced.

The flow plate thus preferably does not serve to separate different media in the region of the flow fields. Rather, because of the ports on both sides of the flow plate, it is common for the same medium to flow therethrough; to moistened and moistened in the course of progressing gas or humid and then gas lower moisture content. This can also be called a monopolar structure; The separation of the gas systems takes place here only via the water transfer membranes.

The plane surface plane z. B. be defined by an edge of the flow plate or by at least three points not lying on a straight line on the edge of the flow plate. Likewise, it is conceivable to define, as plane surface plane of the flow plate, that plane for which a distance integral assumes a minimum value, wherein the distance integral for a given plane is equal to the distance between the flow plate and that plane integrated over the surface of the flow plate. In a variety of stacked flow plates, z. B. in a humidifier, the plane surfaces of the flow plates are usually aligned perpendicular to the stacking direction.

The flow plate may be formed of metal, preferably stainless steel. For example, it may be formed as a metal sheet having a thickness of at most 150 μm, preferably at most 100 μm, particularly preferably at most 80 μm, at a thickness determined at right angles to its plane plane. Metal has a favorable low coefficient of thermal expansion, which can be minimized when temperature fluctuations in the operation of the humidifier occurring mechanical stresses. In particular, this can improve the longevity of the water transfer membranes of the humidifier. Furthermore, it is advantageous if the flow plate is formed in one layer. This reduces the weight of the humidifier and the material costs involved in its manufacture. For micro-sealing or corrosion protection, the flow plate may also be completely or at least partially coated, for. B. by a hydrophilic or a hydrophobic coating.

The flow plate may further comprise guide structures which are arranged and configured such that they guide gas flowing in the region of the flow fields along a flat side of the flow plate through the passage openings to the flow field or into the flow field on the respectively opposite flat side of the flow plate. Thus, a mixing of the gas perpendicular to the plane plane of the flow plate can be further improved. The flow plate and the guide structures can in particular be integrally formed, that is formed from one piece. This can greatly simplify the manufacture of the plate and reduce the manufacturing costs. For example, the lead structures may be molded into the flow plate, e.g. B. by embossing or by deep drawing.

The lead structures may be arranged and configured to abut close the passage openings. Thus, the guide structures can flow the gas flowing along the surface of the flow plate particularly efficiently through the passage openings to the opposite surface of the plate. However, embodiments are also conceivable in which the guide structures or at least some of the guide structures are spaced from the passage openings. For example, the guide structures in this case may be arranged and configured such that they at least partially block the flow of the gas.

The through holes or at least some of the through holes may be punched in the flow plate. It is also conceivable that the passage openings or at least some of the passage openings are formed by cuts in the flow plate, in particular by non-cutting cuts, for example by a line-shaped incision, which is opened either when cutting or subsequently. For example, by means of such incisions and by deforming a region of the flow plate adjoining the incisions, tongue-like, web-like, at least partially dome-shaped or half-shell-like guide structures can be formed in the flow plate. To form the passage openings, these can then be bent out of the plane plane of the flow plate at least in some regions or project from the flow plate. The guide structures or at least some of them can also be designed as webs. The passage openings can then be given for example by open side edges of these webs.

In particular, the guide structures with the planar surface plane of the flow plate can each at least partially include an angle of at least 45 degrees, preferably of at least 75 degrees, particularly preferably of at least 80 degrees. For a height H of the conductive structures determined perpendicular to the plane of the plane of the flow plate, the following applies: 0.5-D <H <10-D, preferably 2-D <H <5-D, where D is the thickness of the flow plate, e.g. B. whose sheet thickness.

In order to support a water exchange membrane or a membrane composite adjoining the flow plate, in particular in the region of the flow field, the conductive structures can be attached to their plate facing away from the ends at least partially aligned parallel to the plane surface plane of the flow plate and / or be bent towards the flow plate. So z. B. damage to the membrane or the membrane composite can be avoided by the lead structures.

The flow plate may have guide structures on both flat sides of the flow plate. Thus, the flow plate may include first conductive patterns and second conductive patterns, the first conductive patterns protruding from the flow plate at the first flat side and the second conductive patterns protruding from the flow plate at the second flat side opposite the first flat side. The first conductive structures may then direct the gas from the first flat side through the through holes to the second flat side, and the second conductive patterns may guide the gas from the second flat side through the through holes to the first flat side. Thus, the mixing of the gas can be further promoted. Usually this improves the flow behavior and mixing of the gas. The passage openings and / or the lead structures may be in periodic

Be spaced apart. For example, the passage openings and / or the guide structures may be arranged parallel to the plane plane of the flow plate along a first direction and along a second direction at periodic intervals to each other. A first distance of adjacent passage openings and / or adjacent guide structures determined along the first direction can then be different from a second distance of adjacent passage openings and / or adjacent guide structures determined along the second direction. The first direction and the second direction may be perpendicular to each other, but may also include an angle of less than 90 degrees. The first guide structures projecting from the first flat side of the flow plate and the second guide structures protruding from the second flat side of the flow plate may be arranged alternately along the first direction and / or along the second direction.

To further improve a mixing of along the plate top Surface guided gas, the guide structures may be formed such that a certain parallel to the plane surface plane of the flow plate cross section of the guide structures is perpendicular to the plane plane of the flow plate in each case variable. So z. For example, gas flowing past the guide structures can be deflected at least partially transversely to the planar surface plane of the flow plate.

For passing a gas to be humidified and a humidified gas or for passing a gas to be dehumidified and a dehumidified gas through the flow plate, the flow plate may further comprise passage openings, wherein the passage openings in fluid communication with the flow fields. The passage openings are usually arranged in the edge regions of the flow plate, in particular in the corner regions. When a plurality of flow plates are stacked in the humidifier, the ports form conduits that extend through the stack in the stacking direction. About these lines, the

Humidifier cells are supplied with gas to be humidified or with gas to be dehumidified. Likewise, dehumidified or humidified gas can be removed from the humidifier cells via these lines. The ports are thus usually in fluid communication with gas ports on an outside of the humidifier, e.g. On at least one of its end plates.

A cross section of a single passage opening is usually larger by a multiple than a cross section of the individual passage openings, for. At least tenfold or at least twentyfold.

For sealing the flow fields and / or the passage openings, the flow plate may further comprise sealing arrangements, for. B. in the form of molded in the flow plate beads. In particular, the sealing arrangements may be arranged around the flow fields and / or around the passage openings and enclose them. To establish a fluid connection between the passage openings and the flow fields, the sealing arrangements or the beads can have openings. In each case, gas can then be passed through the sealing arrangements from the passage openings into the flow fields or from the flow fields to the passage openings via these openings. Alternatively, it is also possible seals up or attach in the form of elastomeric elements. Also proposed is a humidifier, in particular for humidifying process gas for an electrochemical system or for HVAC applications. The humidifier has a plurality of stacked flow plates of the type previously described. Such a humidifier is characterized by great compactness and low production costs by a particularly high efficiency.

Between adjacent flow plates of the stack then usually each a water exchange membrane or a membrane composite is arranged. As described in the introduction, the membrane composite can have, in addition to the water exchange membrane as the support medium, at least one gas diffusion layer, preferably two gas diffusion layers, which are arranged on both sides of the water exchange membrane.

Embodiments of the present invention are illustrated in the figures and will be explained in more detail with reference to the following description. Show it:

Figure 1 shows a humidifier with a variety of stacked

Befeuchterzellen;

FIG. 2 shows an electrochemical system with the humidifier according to FIG

1;

Figure 3 shows known from the prior art flow plates for a humidifier and arranged between the flow plates membrane composite.

FIG. 4 shows an embodiment of a flow plate for a humidifier according to the invention;

FIG. 5 shows a further embodiment of a flow plate for a humidifier according to the invention;

Figure 6a is a sectional view of the flow plate of Figure 4; FIGS. 6b

and FIG. 6c are sectional views of the flow plate according to FIG. 5;

FIG. 7 shows a section of a further embodiment of a flow plate for a humidifier according to the invention;

FIG. 8 shows a further embodiment of a flow plate for a humidifier according to the invention; such as

Figure 9 is a schematic representation of the monopolar Aufba

humidifier according to the invention.

1 shows a perspective view of a block-shaped humidifier 1 with humidifier cells 3 stacked in the stacking direction 2, each containing at least one flow plate and a water exchange membrane, wherein the humidifier cells are interconnected by passage openings aligned in the stacking direction 2 which lead into gas connections 4 leading outwards , 5, 6, 7 lead. The gas connections 4, 5, 6, 7 pass through one of the end plates 8, 9 of the humidifier 1. The gas inlets are provided with the reference numerals 4 and 5 and the gas outlets with the reference numerals 6 and 7. The corresponding gas flow directions are designated A, B, C, D.

The individual humidifier cells 3 stacked in the humidifier 1 each have the same external dimensions, so that stacking produces a cuboid with flat side surfaces.

FIG. 2 schematically shows an electrochemical system 10 with a compressor 11, a humidifier 1 and a fuel cell stack 12, which for example has a large number of hydrogen / oxygen fuel cells. Here and below, recurring features are designated by the same reference numerals. From the compressor 11 to the humidifier 1 via a first input 5 of the humidifier 1, a dry, to be humidified process gas is supplied, for. As molecular hydrogen or molecular oxygen or air. The process gas moistened in the humidifier 1 is then connected to the fuel cell via a first outlet 6 of the humidifier 1. cell stack 12 delivered. There, the chemical energy of different process gases is converted by means of a plurality of membrane electrode units into electrical energy. The exhaust air with the resulting in the reaction of the process gases in the fuel cell stack 12 water is supplied to the humidifier 1 via a second input 4, where it serves for wetting the dry process gas, which is the humidifier 1 via the first input 5, through a water exchange membrane , The dehumidified gas is discharged via a second outlet 7 of the humidifier 1, for example, to the environment.

The capital letters of Figure 2 correspond to the gas flow directions, which are also designated in Figure 1 and are explained in the text for this purpose in connection with the gas connections. Figure 3 shows a perspective view of a known from the prior art humidifier cell 3, to which in the case described two flow plates 13, 14 and disposed therebetween water exchange membrane 15 and two supporting the water exchange membrane 15 on both sides support media 16, 17 in the form of Nonwoven fabrics belong. The edge regions of the water exchange membrane 15 and the support media 16, 17 are not shown in the illustration.

The flow plates 13, 14 each have channels on at least one of their sides, which are separated from one another by webs 14a, 14b. The respective adjacent channels from each other separating webs 14 a, 14 b can be connected to the

Support media 16, 17 abut, so that each enclosed on all sides channels for the flow of a gas to the flow plate within the

Humidifier 3 arise. Gas is supplied to the individual flow plates via the passage openings 18, 19, which gas can be removed again via further passage openings 20 after passing through the respective flow plate. Each flow plate 13, 14 has for this purpose in the example shown on four passage openings, of which two opposing each flat side of the flow plate are assigned. The two other passage openings are each assigned to the opposite flat side and the channels extending there, which are not visible in FIG. The flow plates 13, 14 are in the assembly of a Humidifier stacked so that the passage openings 18, 19 are aligned with each other and form a conduit for supplying gas to all flow plates. On the respective opposite side, a further line for the discharge of gas from the flow plates 13, 14 is formed by the aligned passage openings.

In the humidifier cell 3 shown in FIG. 3, gas flows substantially in the channels of the flow plates 13, 14, which are arranged on both sides of the water exchange membrane 15 and adjoin the membrane 15 in each case, essentially laminar. This can lead to a stationary moisture gradient being set up along the stacking direction 2, that is to say perpendicular to the planar surface planes of the flow plates 13, 14, in such a way that the degree of moisture on the moist side of the humidifier cell 3 decreases towards the water exchange membrane 15 and the moisture level on the dry side of the humidifier cell 3 increases towards the water exchange membrane 15. Since the water transfer rate across the water exchange membrane 15 scales approximately in proportion to the moisture difference immediately adjacent to the membrane 15, the described formation of a steady state moisture gradient in the channels adjacent the membrane 15 will result in an undesirable reduction in water transfer rate. This prior art solution shown in Figure 3 therefore represents a non-optimized embodiment which is to be improved by the present invention. Figure 4 shows a plan view of a first flat side 21 of a single-layer flow plate 22 according to the invention with passage openings 23, 24, 25, 26. The flow plate 22 is a stainless steel sheet having a sheet thickness of z. B. less than 100 μιη trained. The flow plate 22 is part of the plate stack of the humidifier 1 of Figure 1. The passage openings 23, 24, 25, 26 are respectively sealed by sealing beads 30, 31, 32, 33 to the outside and to the interior of the humidifier 1. The flow field 28 is further circulated by a sealing bead 54 which seals the flow field 28 to the outside and to the passage openings 23, 24, 25, 26, wherein the beads are only indicated here. The sealing beads 30, 31, 32, 33 merge into the sealing bead 54. The passage opening 25 is in fluid communication with the

Input 5, via the dry gas from the compressor 11 into the humidifier 1 is initiated. The passage opening 23 is in fluid communication with the outlet 6 of the humidifier 1 (see FIGS. 1 and 2), via which humidified gas is discharged from the humidifier 1 and supplied to the fuel cell stack 12. The passage opening 26 is in fluid communication with the inlet 4, is introduced via the water vapor from the fuel cell stack 12 in the humidifier 1. And the passage opening 24 is in fluid communication with the outlet 7, is discharged through the dehumidified water vapor from the humidifier 1 to the environment.

A second flat side 27 on the side facing away from the viewer back of the flow plate 22 is hidden in Figure 4. Between the passage openings 25 and 23, a first flow field 28 is arranged on the first flat side 21. The passage openings 23, 25 are in fluid communication with the first flow field 28 via apertures 34, 35 in the bead assemblies 30, 32. In a corresponding manner, a second flow field 29 is arranged between the same passage openings 23 and 25 on the second flat side 27, which is likewise concealed in FIG. This second flow field 29 is also in fluid communication with the passage openings 23, 25. During operation of the humidifier 1, dry gas to be humidified, which is supplied to the flow plate 22 via the passage opening 25, flows through the flow fields 28, 29 on either side of the flow plate 22 to the passage opening 23. In the area of the flow fields 28, 29 that flows to the passage opening 23 dry gas then in each case moisture via water transfer membranes (not shown), which adjoin the first flat side 21 and the second flat side 27 on both sides of the flow plate 22. Optionally, gas diffusion layers may also be arranged between the water transfer membranes and the flat sides 21, 27 of the flow plate. The thus moistened in the flow fields 28, 29, the gas is then removed via the passage opening 23 again from the flow plate 22. The passage openings 24, 26 serve to guide moist gas or to discharge dehumidified gas and are not in fluid communication with the flow fields 28, 29 of the flow plate 22, since the surrounding sealing beads 31, 33 have no openings.

Flow plates of the humidifier 1, which are arranged to guide wet gas, may be formed corresponding to the flow plate 22. However, unlike the flow plate 22 shown in Figure 4, the wet gas passageways are then in fluid communication with the flow fields on the flat sides of the flow plate while the dry gas passageways are not in fluid communication with the flow fields. In the humidifier 1, flow plates of the type of the flow plate 22 for guiding dry gas and flow plates for guiding wet gas are alternately arranged.

In Figure 4, the flow fields 28, 29 on the two flat sides 21, 27 of the flow plate 22 by a plurality of through holes 40 in fluid communication with each other. Thus, gas flowing along the flat sides 21, 27 can continuously flow over from the first flow field 28 into the second flow field 29 and from the second flow field 29 into the first flow field 28 on its way from the passage opening 25 to the passage opening 23 through the passage openings 40. For the sake of clarity, only some of the passage openings 40 are designated by reference symbols in FIG. The passage openings 40 are formed in such a way that a vertical projection of the passage openings 40 on the planar surface plane of the flow plate 22, which is aligned parallel to the plane of the drawing in FIG. 4, each has a non-vanishing surface. For example, the projections of the through holes 40 on the plane plane of the flow plate 22 each have an area of at least 0.2 mm ² or at least 0.5 mm ² . But they can also be significantly larger, for example between 1 mm ² and 3.5 mm ² . As a result of this formation of the through-openings 40, the gas flowing in the flow fields 28, 29 has a velocity component perpendicular to the planar surface plane of the flow plate 22 when passing through the through-openings 40, ie along the stacking direction 2 (see FIGS. 1 and 3), so that a Mixing of the gas and carried by the gas and absorbed in the flow fields 28, 29 moisture perpendicular to the plane plane of the flow plate 22 takes place. As described above, this mixing causes an increase in the water transfer rate and the efficiency of the

Humidifier 1.

The passage openings 40 are z. B. punched in the flow plate 22 or punched out of these. It is also conceivable that the passage openings 40 gene by non-cutting, ie linear cutting of the flow plate 22 and by subsequent deformation of the flow plate 22 are formed in the region of the incisions. In order to selectively guide the gas flowing in the flow fields 28, 29 obliquely through the passage openings 40 to the respective other flat side 21, 27, the flow plate 22 on the first flat side 21 in the region of the first flow field 28 has a multiplicity of first guide structures 41 a and on the second flat side 27 in the region of the second flow field 29, a plurality of second conductive patterns 41b. The guide structures 41a, 41b are each formed by deformations in areas of the flow plate 22 adjacent to the passage opening. In FIG. 4, the guide structures 41a, 41b form in each case section-like dome-shaped, spherical or shell-half-shaped elevations which protrude from the flat sides 21, 27 of the flow plate 22 on both sides of the flow plate 22. The first conductive patterns 41a project from the first flat side 21 facing the viewer, and the second conductive patterns 41b protrude from the second flat side 27 facing away from the observer. For example, the guide structures 41a, 41b are each spaced at least 1.5 times the sheet thickness from the flat sides 21, 27.

With the exception of the section of the dome-like guide structures 41a, 41b, in which they adjoin the through-openings 40, the guide structures 41a, 41b have an approximately circular cross-section parallel to the plane of the plane of the flow plate 22, which increases as the plane of the plane of the flow plate 22 increases Distance from the plane of the plane changed, especially tapered. Thus, the gas flowing along the flat sides 21, 27 is additionally impressed with a velocity component perpendicular to the planar surface plane of the flow plate 22, which additionally promotes the mixing of the gas in this direction. Both the passage openings 40 and the guide structures 41a, 41b are here relative to the others

Structures of the flow plate 22, such as the ports 23, 25, are not necessarily drawn to scale. In practice, they will be smaller. The size in the presentation was chosen for ease of understanding. Relative to one another, the passage openings 40 and the guide structures 41a, 41b are shown to scale. The through-openings 40 and the guide structures 41a, 41b are arranged in a lattice-like manner at regular intervals along two mutually perpendicular directions 42, 43, which are respectively aligned parallel to the straight outer edges of the rectangular flow plate 22. Here, the distances between adjacent passage openings 40 and guide structures 41a, 41b are identical in both directions 42, 43. In alternative embodiments, the distances in both directions 42, 43 may also be different. In addition, the lattice-shaped arrangement of the through openings 40 and the guide structures 41a, 41b further Symmetrierichtungen 44, 45, which in each case with the aforementioned directions 42, 43 an angle of approximately

Include 45 degrees. Also along the directions 44, 45, the through holes 40 and the conductive patterns 41a, 41b are arranged at regular intervals. In particular, the first guide structures 41a and the second guide structures 41b are arranged alternately along the directions 44, 45 which are inclined to the outer edges of the flow plates. This arrangement can contribute to the fact that the gas which changes between the flow fields 28, 29 flows from the first flow field 28 into the second flow field 29 in approximately the same extent as in the opposite direction. In this way it can be avoided that local pressure differences build up which could adversely affect the flow behavior and the mixing of the gas.

In addition, it can be seen that the passage openings 40 along the direction 42 or approximately along the flow direction of the gas from the gas inlet serving as the passage opening 25 serving as a gas outlet

Passage opening 23 are respectively disposed at opposite ends of the first conductive patterns 41a and the second conductive patterns 41b. Thus, the passage openings 40 along the direction 42 respectively form that end of the first guide structures 41a, which faces the passage opening 25 serving as a gas inlet. In contrast, the passage openings 40 along the direction 42 respectively form that end of the second guide structures 41b, which faces the passage opening 23 serving as a gas outlet. In alternative embodiments, other arrangements of the passage openings 40 relative to the guide structures 41a, 41b are conceivable. For example, the through-openings 40 could also adjoin the end of the first guide structures 41a and the second guide structures 41b, that as the gas outlet serving passage opening 23 faces (see Figure 7).

To illustrate the geometry of the first guide structures 41a on the first flat side 21 of the flow plate 22 of Figure 4, a section through the flow plate 22 along the section line B-B is shown in Figure 6a.

Highlighted are the first flat side 21, the second flat side 27, the passage openings 40 arranged at regular intervals along the direction 42 and the first guide structures 41a arranged at regular intervals along the direction 42, each of which directly adjoin the passage openings 40. The through-openings 40 make visible a fluid connection between the first flow field 28 on the first flat side 21 and the second flow field 29 on the second flat side 27 forth. The first conductive patterns 41a protrude from the first flat side 21, approximately three times the sheet thickness. Due to the convexity of the first power structures 41a with respect to the flat side 21, the gas flowing from the first flow field 28 on the first flat side 21 into the second flow field 29 on the second flat side 29 will pass through the passage openings 40 adjacent to the first conductive patterns 41a Impacted velocity component, which is aligned perpendicular to the plane plane of the flow plate 22. The

Flow of the gas through the passage openings 40 and the guiding action of the first power structures 41a is highlighted by flow arrows 46 in FIG. 6a by way of example. FIG. 5 shows a further embodiment of a flow plate 47 according to the invention. Sections through the flow plate 47 along the sectional lines C-C and D-D shown in FIG. 5 are shown in FIGS. 6b and 6c, wherein the sectional plane is oriented perpendicular to the plane of plan plane of the flow plate 47.

The flow plate 47 of Figure 5 differs from the flow plate 22 of Figure 4 by a partially different type of flow fields 28, 29 on the flat sides 21, 27. In addition to the described in connection with the flow plate 22 in approximately circular through holes 40 and the dome-like or shell-shaped half

Lead structures 41a, 41b, the flow plate 47 additionally elongated, on the rounded end openings 48 and to the through holes 48 adjacent lead structures 49. About the passage openings

48, the flow fields 28, 29 on the opposite flat sides 21, 27 of the flow plate 47 are in fluid communication with each other. And, like the through holes 40, a projection of the through holes 48 on the plane plane of the flow plate 47 has a non-vanishing surface. In Figure 5, the plane plane of the flow plate 47 is aligned parallel to the plane of the drawing. Depending on a longitudinal extent of the through openings 48, this surface z. At least 1 mm ² , at least 2 mm ² or at least 3 mm ² . For very wide through holes 48, this area may well be more than 10 mm ² or even more than 20 mm ² . Typical widths are in the range of 0.5 mm to 2.5 mm, but smaller or larger widths, about 0.5 mm or, for example, 3.5 mm are also possible.

Like the through-holes 40, the through-holes 48 may be punched or punched out of the metal sheet from which the flow plate 47 is formed. Alternatively, the passage openings 48 may be formed by cuts, in particular non-cutting cuts, in the flow plate 47. For example, they form one piece with the flow plate

47 trained and molded into the flow plate 47 guide structures

49 webs with an open side edge along one longitudinal side. In the embodiment shown in FIG. 5, the conductive structures 49 are offset from the first flat side 21 by at least three sheet thicknesses. The passage openings 48 and the webs forming the guide structures 49 extend into

Longitudinal over a length, the z. B. at least 15 percent, at least 30 percent or at least 70 percent of a length of the shorter longitudinal side of the rectangular flow plate 47 is. These webs may in turn have a convex curvature at least in sections with respect to the flat side 21, so that the guide structures 49 impart a velocity component perpendicular to the plane of the plane of the flow plate 47 to the gas as it flows through the through-openings 48.

The passage openings 48 and the guide structures 49 are aligned approximately transversely to the flow direction of the gas, which in the operation of the humidifier 1 from the serving as a gas inlet passage opening 25 along the flat sides 21, 27 through the flow fields 28, 29 to serve as a gas outlet passage opening 23 flows. In particular, the elongated passage openings 48 and the elongate guide structures 49 are aligned approximately transversely to the shortest straight line connecting the passage opening 25 and the passage opening 23. For example, the elongated passage openings 48 and the elongated guide structures 49 with this shortest straight line connecting the passage opening 25 and the passage opening 23 at an angle here between 60 degrees and 70 degrees. In principle, the angle can be chosen freely and is preferably over 60 degrees. In particular, the size of the angle depends on whether a through opening 48 or guide structure 49 is arranged parallel to an outer edge or obliquely to both outer edges of the flow plate and of the outer geometry of the flow plate. On account of this embodiment of the passage openings 48 and the guide structures 49, the gas flowing from the passage opening 25 to the passage opening 23 can be directed particularly efficiently from the first flow field 28 on the first flat side 21 into the second flow field 29 on the second flat side, or vice versa. In addition, the flow plate has closed guide structures 50, each of which protrudes like a dome or sphere from the second flat side 27 of the flow plate, z. B. at least three times the sheet thickness. Parallel to the planar surface plane of the flow plate 47, the guide structures 50 have a round cross-section, which decreases with increasing distance from the plane of the plane.

FIG. 7 shows a section of a flow plate 51, which is a slightly modified variant of the flow plate 22 from FIG. The flow fields 28, 29 of the flow plate 51 of FIG. 7 differ from the flow fields 28, 29 of the flow plate 22 of FIG. 4 in that the passage openings 40 each adjoin those ends of the guide structures 41a, 41b which face the passage opening 23 serving as the gas outlet are (not shown). FIG. 7 also shows a

Sectional view of the flow plate 51 along the section line AA, wherein the sectional plane is again aligned perpendicular to the plane plane of the flow plate 51, which is parallel to the drawing plane as before. Once again, it can be seen that the passage openings 40 and the guide structures 41a, 41b are arranged periodically along the directions 42, 45. The distances of immediately adjacent through holes 40 and Immediately adjacent guide structures 41a, 41b are larger along the direction 42 than along the direction 45.

FIG. 8 shows a flow plate 52, which is a further modification of the flow plate 22 of FIG. The flow plate 52 from FIG. 8 differs from the flow plate 22 according to FIG. 4 in that the flow fields 28, 29 have channel structures 53 on the flat sides 21, 27 next to the through openings 40 and the guide structures 41a, 41b. The channel structures 53 are formed in the metal sheet from which the flow plate 52 is formed, for. B. by embossing or by deep drawing. The channel structures 53 are configured to conduct gas from the gas inlet serving as a gas inlet passage opening 25 to serve as a gas outlet passage opening 23 through the flow fields 28, 29. Furthermore, in the flow plate 52, some conductive patterns 41a '41b' are rotated by 90 ° relative to the remaining conductive patterns 41a, 41b, as are the through holes 40 'disposed in the region of these conductive patterns 41a', 41b 'at 90 ° to the remaining through holes 40 are. As a result, the gas streams can be directed to or from the outer regions of the flow fields 28, 29. It would also be possible to arrange different passage openings and guide structures at many different angles relative to each other in order to achieve optimum flow and mixing of the gas streams.

By contrast, FIG. 9 shows a monopolar structure of a humidifier module or of a section of a humidifier having two different flow plates 13, 14. The flow plates 13 are arranged between two flow spaces of moist gas ("W"), the flow plates 14 between two flow spaces of drier gas ("D"). The flow plates 13, 14 each have passages, so that the two adjacent flow spaces are not completely separated from each other.

Instead of two different flow plates, at least in some cases, only a single flow plate can be used, which is installed with different orientations, so that 13 and 14 still differ from each other.

Claims

claims

A flow plate (22, 47, 52) for a humidifier (1), in particular for a humidifier (1) for humidifying process gas for an electrochemical system or for a humidifier (1) for HVAC applications, with flow fields (28, 29 ) on both opposite flat sides (21, 27) of the flow plate (22; 47; 52) and with a plurality of passage openings (40, 48) in the region of the flow fields (28, 29), the passage openings (40, 48) being such in that a vertical projection of the openings (40, 48) on a plane parallel to the planar surface plane of the flow plate (22; 47; 52) has a non-vanishing surface, so that through the passage openings (40 , 48) gas at least partially effects a mixing of gas guided in the flow fields (28, 29) perpendicular to the plane of the plane of the flow plate (22; 47; 52).

2. Flow plate (22; 47; 52) according to claim 1 with guide structures (41a, 41b, 49), which are arranged in the region of the flow fields (28, 29) along the plate surfaces flowing gas through the passage openings (40, 48) therethrough to the flow field (28, 29) or into the flow field (28, 29) on the respective opposite flat side (21, 27) of the flow plate (22, 47, 52) to guide and so a mixing of the gas perpendicular to the plane plane of the flow plate (22 47, 52).

A flow plate (22; 47; 52) according to any one of the preceding claims, wherein the flow plate (22; 47; 52) is formed of metal, preferably stainless steel.

4. flow plate (22, 47, 52) according to one of the preceding claims, which is designed as a metal sheet with a thickness of at most 150 μιη determined by the plane of the flow plane (22; 47; example of at most 100 μιη, particularly preferably of at most 80 μιη is formed.

5. Flow plate (22; 47; 52) according to one of the preceding claims, wherein the flow plate (22; 47; 52) is formed in one layer.

A flow plate (22; 47; 52) according to any one of claims 2 to 5, wherein the flow plate (22; 47; 52) and the lead structures (41a, 41b, 49) are integrally formed.

7. flow plate (22; 47; 52) according to any one of claims 2 to 6, wherein the guide structures (41a, 41b, 49) in the flow plate (22; 47; 52) formed, in particular embossed.

The flow plate (22; 47; 52) according to any one of claims 2 to 7, wherein the lead structures (41a, 41b, 49) respectively extend to the dowel openings (40, 48).

A flow plate (22; 47; 52) according to any one of the preceding claims, wherein the passage openings (40,48) are at least partially punched in the flow plate (22; 47; 52).

A flow plate (22; 47; 52) as claimed in any one of the preceding claims, wherein the passage openings (40,48) are formed by cuts in the flow plate (22; 47; 52).

11. flow plate (22; 47; 52) according to claim 10, wherein the incisions form tongue-like, web-like or conch-like guide structures (41a, 41b, 49) which are at least partially formed from the plane plane of the flow plate (40, 48) for forming the through openings (40, 48). 22; 47; 52), preferably at least partially perpendicular to the plane of plan plane of the flow plate (22; 47; 52).

12. flow plate (22, 47, 52) according to one of claims 2 to 11, wherein the guide structures (41a, 41b, 49) with the plane plane of the Strö- each at least in sections form an angle of at least 45 degrees, preferably of at least 75 degrees, particularly preferably of at least 80 degrees.

13. Flow plate (22, 47, 52) according to one of claims 2 to 12, wherein the guide structures (49) are formed as webs, each having an open side edge.

A flow plate (22; 47; 52) according to any one of claims 2 to 13, wherein the guide structures (41a, 41b, 49) are supported at their ends protruding from the flow plate (22; 47; 52) for supporting a water exchange membrane (15) or a membrane composite aligned at least in sections parallel to the planar surface plane and / or to the plane surface plane of the flow plate (22; 47; 52) are bent back out.

A flow plate (22; 47; 52) according to any one of claims 2 to 14, comprising first guide structures (41a, 49) disposed on the first flat side (21) of the flow plate (22; 47; 52) of the flow plate (22; 52), and second guide structures (41b) projecting from the flow plate (22; 47; 52) on the second flat side (27) of the flow plate (22; 47; 52) opposite the first flat side (21).

16. Flow plate (22; 47; 52) according to one of the preceding claims, wherein the passage openings (40, 48) and / or the guide structures (41a, 41b) are arranged at periodic intervals to one another.

17. A flow plate (22; 47; 52) according to claim 16, wherein the through openings (40) and / or the guide structures (41a, 41b) are parallel to the plane of plan plane of the flow plate (22; 47; 52) along a first direction (42) and along a second direction (43, 45) are arranged at periodic intervals to each other.

18. A flow plate (22; 47; 52) according to claim 17, wherein a first distance of adjacent passage openings (40) and / or adjacent guide structures (41a, 41b) determined along the first direction (42) is determined by a first distance. Long of the second direction (45) certain second distance between adjacent through holes (40) and / or adjacent guide structures (41a, 41b) is different.

The flow plate (22; 47; 52) according to claim 17 or 18, wherein the first direction (42) and the second direction (43) are perpendicular to each other.

20. The flow plate (22; 47; 52) according to claim 15 and any one of claims 17 to 19, wherein the first guide structures (41a, 49) projecting from the first flat side (21) of the flow plate (22; 47; 52) and the from the second flat side (27) of the flow plate (22; 47; 52) projecting second guide structures (41b) along the first direction (42) and / or along the second direction (45) are arranged alternately.

21. A flow plate (22; 47; 52) according to any one of the preceding claims, wherein the flow fields (28, 29) have channel structures (53).

The flow plate (22; 47; 52) according to any one of claims 2 to 22, wherein the lead structures (41a, 41b, 49) are formed to improve mixing of gas guided along the plate surface such that a parallel to the plane plane of the flow plate (41). 22; 47; 52) has a certain cross-section of the guide structures (41a, 41b, 49) along a direction perpendicular to the plane of the plane of the flow plate (22; 47; 52) is variable in each case.

A flow plate (22; 47; 52) according to any one of the preceding claims having passage openings (23, 24, 25, 26) for passing a gas to be humidified and a humidified gas or gas to be dehumidified and a dehumidified gas through the flow plate (22 47, 52), wherein the passage openings (23, 24, 25, 26) are in fluid communication with the flow fields (28, 29).

A humidifier (1), in particular for humidifying process gas for an electrochemical system or for HVAC applications, comprising a plurality of stacked flow plates (22; 47; 52) according to any one of the preceding claims.

A humidifier (1), in particular for humidifying process gas for an electrochemical system or for HVAC applications, comprising a plurality of stacked flow plates (22; 47; 52) according to claim 23, wherein the passage openings (23, 24, 25, 26 The flow plates (22; 47; 52) of the stack are arranged in alignment and form conduits for guiding a gas to be humidified, a humidified gas, a gas to be dehumidified and a dehumidified gas through the stack.

A humidifier (1) according to any one of claims 24 or 25, wherein a water exchange membrane (15) or membrane composite is disposed between adjacent flow plates (22; 47; 52) of the stack, the membrane composite comprising a water exchange membrane (15) and at least one water exchange membrane (15) Gas diffusion layer (16, 17), preferably two gas diffusion layers (16, 17) which are arranged on both sides of the water exchange membrane (15).